From 935070a8f182ab92bfca51606e49ee2b62e51e55 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Steinbrink?= Date: Wed, 3 Jan 2018 10:29:27 +0100 Subject: [PATCH] Don't force-enable frame pointers when generating debug info We apparently used to generate bad/incomplete debug info causing debuggers not to find symbols of stack allocated variables. This was somehow worked around by having frame pointers. With the current codegen, this seems no longer necessary, so we can remove the code that force-enables frame pointers whenever debug info is requested. Since certain situations, like profiling code profit from having frame pointers, we add a -Cforce-frame-pointers flag to always enable frame pointers. Fixes #11906 --- src/librustc/session/config.rs | 6 ++++++ src/librustc/session/mod.rs | 2 +- src/librustc_trans/attributes.rs | 2 -- src/test/codegen/force-frame-pointers.rs | 16 ++++++++++++++++ 4 files changed, 23 insertions(+), 3 deletions(-) create mode 100644 src/test/codegen/force-frame-pointers.rs diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs index 736d7f8a1396..df4ae1e24619 100644 --- a/src/librustc/session/config.rs +++ b/src/librustc/session/config.rs @@ -1064,6 +1064,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options, 2 = full debug info with variable and type information"), opt_level: Option = (None, parse_opt_string, [TRACKED], "optimize with possible levels 0-3, s, or z"), + force_frame_pointers: bool = (false, parse_bool, [TRACKED], + "force frame pointers to be used"), debug_assertions: Option = (None, parse_opt_bool, [TRACKED], "explicitly enable the cfg(debug_assertions) directive"), inline_threshold: Option = (None, parse_opt_uint, [TRACKED], @@ -2890,6 +2892,10 @@ mod tests { opts.cg.debuginfo = Some(0xba5eba11); assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash()); + opts = reference.clone(); + opts.cg.force_frame_pointers = true; + assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash()); + opts = reference.clone(); opts.cg.debug_assertions = Some(true); assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash()); diff --git a/src/librustc/session/mod.rs b/src/librustc/session/mod.rs index 3f52ecfc0999..46c69d052301 100644 --- a/src/librustc/session/mod.rs +++ b/src/librustc/session/mod.rs @@ -20,7 +20,7 @@ use lint::builtin::BuiltinLintDiagnostics; use middle::allocator::AllocatorKind; use middle::dependency_format; use session::search_paths::PathKind; -use session::config::{DebugInfoLevel, OutputType}; +use session::config::{OutputType}; use ty::tls; use util::nodemap::{FxHashMap, FxHashSet}; use util::common::{duration_to_secs_str, ErrorReported}; diff --git a/src/librustc_trans/attributes.rs b/src/librustc_trans/attributes.rs index d5ec8d1b5526..d57e5040045c 100644 --- a/src/librustc_trans/attributes.rs +++ b/src/librustc_trans/attributes.rs @@ -65,8 +65,6 @@ pub fn naked(val: ValueRef, is_naked: bool) { } pub fn set_frame_pointer_elimination(cx: &CodegenCx, llfn: ValueRef) { - // FIXME: #11906: Omitting frame pointers breaks retrieving the value of a - // parameter. if cx.sess().must_not_eliminate_frame_pointers() { llvm::AddFunctionAttrStringValue( llfn, llvm::AttributePlace::Function, diff --git a/src/test/codegen/force-frame-pointers.rs b/src/test/codegen/force-frame-pointers.rs new file mode 100644 index 000000000000..d40406a0476f --- /dev/null +++ b/src/test/codegen/force-frame-pointers.rs @@ -0,0 +1,16 @@ +// Copyright 2018 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. +// +// compile-flags: -C no-prepopulate-passes -C force-frame-pointers + +#![crate_type="lib"] + +// CHECK: attributes #{{.*}} "no-frame-pointer-elim"="true" +pub fn foo() {}